Many electronic devices can enter a reduced power mode, e.g., a sleep mode or an off mode, when appropriate to save power. A controller can send a command to a device to enter a reduced power mode using an interface, e.g., a serial peripheral interface (SPI) bus. However, when the device is in the reduced power mode, the device may not be able to use the SPI bus to receive a command to exit the reduced power mode. Some devices have an additional pin to receive a signal from a controller indicating a command to exit the reduced power mode. For example, a device can have an interface with five pins: four for the SPI bus (clock, data in, data out, and select) and one for controlling the power state.